1. Field of the Invention
The invention relates to a method and apparatus for permanently locking open a well flow control device, such as a safety valve, which is mounted on a tubular conduit in a subterranean well.
2. Description of the Prior Art
In order to control the flow of hydrocarbons from a production zone or zones within a subterranean well through one or more production conduits, it is desirable and in the United States mandatory by governmental regulations, for offshore wells to provide each production conduit with a downhole safety valve, which is reciprocatingly movable between an open and closed position by a variation in the hydraulic control fluid pressure which is in communication with the valve structure through a control line conduit extending from the top of the well, such as from a control panel on the platform, or the like.
Occasionally, a well flow control device will lose its closing or fluid tight integrity, for example, as a result of debris within the fluid being transmitted into the flow control device at the top of the well and becoming entrapped between sensitive working components of the device, or as a result of the valve being slammed closed upon its valve seat during testing procedures. Therefore, it is necessary for such a well flow control device to include a means for permanently placing the well flow control device in a "locked open" position, so that thereafter, an auxiliary flow control device, such as a wire line manipulated safety valve device, can be emplaced within the production conduit.